The ero-mangaka Daisuke was drawing ero manga using as a model her childhood friend Mizuki. Mizuki suddenly comes and asks Daisuke what he is doing. Seeing how she is being using as a model she wonders of she should actually gave some real inspiration to Daisuke so he can develops a btter ero manga.Azusa and hiro are siblings. Azuza’s libido once a month becomes bottomless. And then that day has come again, thus, Hiro must dedicate all his attention and efforts that day to satiate her sister Azusa’s sexual desires. will he has the energy needed for such huge task? Hiro can only wonder when this apparently “heaven” will end, his mother advice him that she was the same as Azusa when she was younger and the “cure” was having a baby.